Safety car brake equipment



July 26, 1938. E. E. HEwlTT SAFETY CAR BRAKE EQUIPMENT 2 Sheets-Sheet 1 Filed 001;. 14, 1936 `Iuly 26, 1938. E. E. HEWITT SAFETY CAR BRAKE EQUIPMENT Filed oct. 14, 193e 2 Sheets-ShamI 2 www www n www.

INVENTOR L LIE EHEWITT BY Wn ATTORNEY Patented July 26, 1938 UNITED STATES PATENT OFFIQE SAFETY CAR BRAKE EQUIPMENT' Application October 14, 1936, Serial No. 105,448

8 Claims.

This invention relates to safety car brake equipment, and particularly to safety car brake equipment of the character shown and described in mycopending application Serial No. 26,394, filed June 13, 1935, and assigned to the assignee of the present application.

`In the above copending application, there is disclosed a safety car brake equipment including a pair of 4deadrnan control devices functioning when both are simultaneously released to automatically cause a so-called deadmans emergency application of the brakes. Means is also provided in the copending application whereby a deadmans emergency application of the brakes is prevented or suppressed if, at the time that the deadrnans control devices are released, at least a predetermined degree of service application of the brakes has been effected by the service application control device.

In the copending application, with the brake equipment operated to effect at least the predetermined degree of service application of the brakes to suppress a deadmans emergency application of the brakes, an emergency application oi' the brakes cannot be effected except by operation of a so-called conductors valve device.

It is an object of my present invention to provide a safety car brake equipment having means whereby the operator may effect an emergency application of the brakes at any time, by operation of the same foot pedal element employed for effecting service applications of the brakes, notwithstanding that at the time a service application of the brakes is in eifect or that a deadman emergency application of the. brakes is being suppressed.

Another object of my invention is the provision, in a safety car brake equipment having a retardation controller device for automatically controlling the application and the release of the brakes so as to regulate the retardation oi' the vehicle or train to a certainrsubstantially constant rate of retardation. of suitable means effective only for safety control oremergency applications of the brakes, upon the operation of the retardation controller to release fluid under pressure previously supplied to effect anV application of the brakes. for limiting the reduction in the pressure eifected by the retardation controller toa certain minimum pressure, thereby insuring the maintenance of an adequate braking force sufficient to bring the vehicle or train to a safe stop. Y i

Another object of my invention is the provision, in a safety car brake equipment having apparatus for effecting an emergency application of the brakes, of means for insuring at least a certain predetermined degree of application of the brakes following the initiation of an emergency application of the brakes, adequate to safely stop the vehicle or train.

Another object of my invention is the provision, of a safety car brake equipment having the combination of an inertia operated retardation controller responsive to changes in speed of the car or train for so controlling the application and the release of all the separate brake units as to regulate the rate of retardation of the car or train to a substantially constant rate of retardation, and a separate automatically actuated means for each brake unit for separately controlling the release and reapplication of individual brakes or brake units so as to prevent sliding of the associated wheel or wheels.

A further object of my invention is the provision, in a safety car brake equipment including a self-lapping valve device manually operable to effect service applications of the brakes and other apparatus controlled by deadman devices for effecting emergency applications of the brakes, of suitable means whereby to lock the self-lapping valve ldevice in application position to permit the complete release of all deadman brakes and without effecting a release of the brakes.

The above objects, and other objects of my invention which will be made apparent subsequently, are attained by means of an illustrative embodiment of a safety car brake equipment described hereinafter as shown in the accompanying drawings, wherein,

Fig. 1 and Fig. 2 taken together constitute a diagrammatic view of the essential elements comprising a safety car brake equipment embodying the features of my invention,

Fig. 3 is a sectional view, taken on line 3-3 of Fig. 1, showing details of construction of the anti-wheel-sliding device.

Fig. 4 is a sectional view, taken on the line 4-4 of Fig. 1, showing the construction of the antiwheel-sliding device in further detail,

Fig. 5 is a fragmentary sectional View, taken 0n the line 5 5 of Fig. 2, showing in further detail the construction of an electric controller device for controlling the application of the magnetic track shoe brakes.

Brief description of equipment Briefly, the equipment, shown in Figs. 1 and 2,

Y comprises a uid pressure brake system exemplifled by a brake cylinder I0, a control valve mechanism II for controlling the supply and release of fluid under pressure to and from the brake tioning jointly and cooperatively to so control the operation of the control valve mechanism II as to cause a deadman emergency application of the brakes. A cut-out valve device I5 is provided which is effective when at least a certain uniform brake cylinder pressure is obtained to render the deadman control devices I3 and I4 ineffective to cause a deadman emergency application of the brakes. A locking mechanism I6 associated with the control valve mechanism II is operative, upon the simultaneous release of both of the deadman control devices I3 and I4, to .prevent operation of the control valve mechanism I I to reduce brake cylinder pressure, thereby enabling the complete removal of the operators foot from the brake pedal I2 and causing the cut-off valve device I6 to remain effective to suppress or prevent a deadman emergency application of the brakes.

According to my invention a vent valve device 22 is provided which is effective to cause operation of the control valve mechanism II resulting in an emergency application of the brakes, the vent valve device being operated only when the brake pedal I2 is fully depressed that is, through and beyond the service application zone.

Also functioning as a part of the iluid pressure brake systemis a retardation controller device I8 which operates on the control valve mechanism II to so control the brake cylinder pressure as to maintain a substantially `constant selected rate of retardation. Also included in the fluid pressure brake system is an anti-wheelsliding 4device I9 which is eiTective, through a magnet valve device 20 and a control valve device 2I, to eiTect release of fluid under pressure from the brake cylinder I0.

The equipment shown further comprises a magnetic track brake system including a magnetic track shoe brake device 23, and a magnet valve device 24 for controlling the raising and lowering of the track shoe brake device 23. An electric controller device 25 is operated by the brake pedal I2 for controlling the degree of 'energization of the electro-magnet on the magnetic track shoe device 23 as well. as the operation of the raising and lowering magnet` valve device 24 for service applications of the brakes. A pneumatic switch device 26 functions in emergency applications of the brakes, independently of controller 25, for effecting application .ofl the magnetic track shoe brakes to the maximum degree. y

Detailed description,v of equipment :',Valve device 20', and a control valve device similar 'to the control valve device 2I is provided for each brake cylinder. In a similar manner, it will be understood that in practice a plurality of magnetic track shoe devices similar to the magnetic track shoe device 23 will be provided which are controlled and operated in a manner similar to that of the magnetic track shoe device 23.

Referring first to Fig. 2, the control valve mechanism II comprises a casing having a pipe bracket section 3I to which are suitably secured in sealed relation by suitable bolts or screws, not shown, a self-lapping valve section 32, an emergency valve section 33, and a magnet valve section 34.

Embodied in the casing section 32 is a selflapping valve device 35 comprising a supply valve 3l in the form of a valve piston which operates slidably in a bore 38 in the casing section 32, and a release valve 4I which is carried on a piston or movable abutment 42 that operates in a bore 43 in the casing section 32. The bore 43 opens at the inner end thereof into a chamber 44, hereinafter termed the pressure chamber, and opens at the outer end thereof to the exterior of the casing. The supply lvalve 3l isyieldingly urged into seated relation on a valve seat, formed on a bushing 45 secured to the casing section 32, by a spring 46 which is interposed between the valve 3l and a screw-threaded nut 41 turned into the outer threaded portion of bore 38. The supply valve 31 is effective, when unseated against the force of the spring 46, to open communication between the pressure chamber 44 and a chamber 48, which is constantly connected to the main reservoir 9 through a passage and pipe 49 and a branch pipe 5I.

The release valve 4I is in the form of a pin valve having a reduced portion or stem 50 at one end which operates slidably in a longitudinally extending bore 52 at the central axis of the piston 42, the opposite end of the release valve extending into the pressure chamber 44 and having a collar or ange 53 which is guided in a recess 54 in the piston 42 open t0' the pressure chamber. The release valve 4I is normally yieldingly unseated from a cooperating valve seat on the piston 42 by a spring 55 which surrounds the valve 4I in the recess-54 and which is disposed between the inner end of the recess -54 and the iiange 53. A washer or collar 56, removably secured to the inner face of the piston 42, has a central perforation through which the inner end of the pin valve 4I extends-into the chamber 44 and serves as a stop for the ange 53 on the pin Valve 4I to limit the unseating movement of the valve 4I with respect to its valve seat. The release valve 4I is disposed in a chamber 5'I in the piston 42, which is constantly connected to the pressure chamber 44 through a passage 58, and controls communication from the chamber 5'I through a central bore 59 in the piston and one or more branch passages 6I to a chamber 62 at the opposite'side of the piston 42 which is constantly open to atmosphere through a port 63.

The piston 42 has a central stem 64 which operates slidably in a bore 65 formed centrally ina screw 66 screwed into the outer threaded portion of the bore 43. Disposed inthe chamber 62 between the screw 66 and the face of'theipiston 42 is a spring 61 which` serves to yieldingly urge' the piston 42 inwardly of the bore 43 toward the pressure chamber 44. The tension of the spring 6'I may be adjusted by turning the screw 66 inwardly or outwardly of the bore 43.

The outer end of the central bore 65 in the screw 66 is threaded to receive a set screw 68 which is engageable by the stem 64 on the pis- 75 ton 42 and serves as a stop for the outward movement of the piston in the bore 43. A lock nut 69 is screwed over the set screw 68 and into contact with the casing section 32 to lock the set screw 68 in position.

Operation of the supply valve 31 and the release valve 4| is effected by means of a floating lever 1| which is pivoted intermediate the ends thereof, as by a pin 12, on a plunger 13 that 'operates slidably in a bore 14 in the casing, the

bore 14 being between the bores 38 and 43 and in substantially parallel relation thereto` Carried at one end of the lever 1| is a roller 15, which is adapted to engage the inner end of the release valve 4|, and pivoted as by a pin 10 at the opposite end of the lever 1| is an operating rod 16 which is adapted to extend into a recess 11 formed in the face of the supply Valve 31.

' A shaft 19 is suitably journaled to the casing section 32 in a manner not shown and extends through the pressure chamber 44 substantially at right angles to the line of movement of the plunger 13 and carries a cam 8| thereon which is securely fixed thereto and adapted to engage the inner end of the plunger 13 to urge the plunger 13 upwardly in the bore 14 upon a clockwise rotation of the shaft 19, as Viewed in Fig. 2.

Secured to the shaft 19 at a portion thereof exterior tothe casing section 32 is an operating arm 83, and a spring 84 is secured at one end to the outer end of the arm 83 and at the opposite end to a lug 85 on the casing section 32 to yieldingly bias the arm 83 and the shaft 19 in a counterclockwise direction into the normal position thereof as shown.

Pivotally connected to the lever arm 83 at a suitable point thereon, as by an eyelet or clevis 86, is a iiexible cable or a rigid tie rod 81, the opposite end of which is connected to the outer end of one arm of a bell-crank lever 88. (Fig. l.) The bell-crank lever 88 is pivotally mounted, as by a pin 89, on a bracket 9| attached to the floor 92 of the car of the vehicle and the brake pedal I2 is secured to or formed integrally with the bellcrank lever 88 in such manner that the application of pressure to the brake pedal 2 applies force to the outer end of the other arm of the bell-crank lever 88. Thus, when the brake pedal I2 is depressed toward the floor 92, the bell-crank lever 88 is rotated on the pin 89 in a counterclockwise direction, as viewed in Fig. 1, and the consequent pull exerted on the cable or rod 81 overcomes the spring 84 and causes rotation of the lever arm 83 and the shaft 19 in a clockwise direction, as viewed in Fig. 2.

The spring 46 acting on the supply valve 31 is more strongly tensioned than the spring 55 acting on the release Valve 4|, and thus initial rotation of the cam 8| in a clockwise direction to shift the plunger 13 upwardly in the bore 14 causes the lever 1| to pivot on the pin 10 in a counterclockwise direction to overcome the force of the spring 55 and seat the release valve 4| to close communication between the pressure chamber Y44, at one side of the piston 42 and the atmospheric chamber 62 at the opposite side of the piston 42, The spring 61 acting on the piston 42 is stronger in tension than the'spring 46 acting on a supply valve 31 and consequently, after the release valve 4| is seated, the continued rotation of the cam 8| in a clockwise direction causes the lever 1| topivot on the roller 15 in a clockwise direction to unseat the supply valve 31 against the force of the spring 46. Fluid under pressure is accordingly supplied from the main reservoir 9 to the pressure chamber 44.

As the pressure of the flui-d supplied to the chamber 44 increases, the spring 61 is overcome by the fluid pressure in chamber 44 acting on the piston 42 and the piston is thus moved outwardly of the bore 43. The spring 46 acting on the supply valve 31 thus becomes effective through the supply valve 31 and the operating rod 16 to rock the lever 1| about the pin 12 in a counterclockwise direction until the supply valve 31 is seated, while at the same time maintaining the release valve 4| seated.

Upon further rotation of the cam 8| in a clockwise direction. the supply valve 31 is again unseated to again supply fluid under pressure from the main reservoir 9 to the pressure chamber 44 and when the pressure in the chamber 44 increases sufficiently, depending upon the position of the cam 8|, toovercome the spring 61, the spring 46 again becomes effective to reseat the supply valve 31 and cut off the further supply of fluid under pressure to the pressure chamber 44.

When the pressure in the pressure chamber 44 has increased sufficiently so that the stem 64 of the piston 42 engages the set screw 68, the spring 46 is ineffective to return the supply valve 31`to seated position because the outward movement of piston 42 necessary to permit rocking of the lever 1| in a counterclockwise direction on the pin 12 is prevented. Accordingly the supply valve 31 remains open and fluid under pressure continues to be supplied from the main reservoir 9 into the pressure chamber 44 to cause a maximum pressure, corresponding to the pressure of the main reservoir 9, to be produced in the chamber 44.

When the pressure on the foot pedal I2 is relieved. the spring 84 becomes effective to return the lever arm 83. the shaft 19, and the cam 8| in a reverse or counterclockwise direction. Assuming that a certain pressure has been established in the pressure chamber 44 and that both the supply valve 31 and the release valve 4| are seated. the return of the cam 8| in a counterclockwise direction renders the spring 55 acting on the release valve 4| effective to unseat the release valve to thereby establish communicaytion through` which the fluid under pressure in the chamber 44 is exhausted to atmosphere by way of the passage 58, chamber 51, bore 59, passages 6|, chamber 62 and port 83. As the pressure in the pressure chamber 44 diminishes. the spring 61 becomes effective to shift the piston 42 inwardly of the bore 43, that is, toward the pressure chamber 44, and assuming that the cam 8| is held in position., ultimately shifts the piston 4? to reseat the pin valve 4| on its valve seat to close off the exhaust of fluid under pressure from the pressure chamber 44. When. the cam 8| is returned a further extent toward its normal position, the further release of fluid under pressure from the pressure chamber 44 is effected in a similar manner. It will be apparent that the supply valve 31 remains seated to cut olf the supply of fluid under pressure from the main reservoir 9 to the pressure chamber 44 as the cam 8| is returned toward its normal position in a counterclockwise direction because movement of the piston 42 inwardly of the bore 43, as the pressure in the pressure chamber 44 reduces, is stopped the instant that the release valve 4| is reseated, and thus the lever 1| is not rocked or pivoted in a clockwise direction on the pin 12 to unseat the Valve 31.

When the cam 8| is returned fully to its normal or release position, the spring 51 is ineffective to cause reseating of the release valve 4| and conse uently the exhaust communication for the pressure chamber 44 through the atmospheric port 63 remains open.

The emergency valve casing section 33 contains an emergency valve device 40 comprising a piston 95 which has at one side thereof a piston-chamber 95 constantly connected by a branch pipe 91 to a pipe 98, hereinaftertermedthe safety control pipe, and having at the other -side thereof a valve chamber SiS-which is constantly charged withfluid under pressure from the main reservoir 9 through a vpassage y|0| connecting the chamber 99 with the main reservoir passage and pipe 49. Contained in the .Valve chamber 99 is a sli-de valve |02 whichV is secured between the end flange on a stem |03 of the piston 95 and a shoulder on the piston and shifted on a cooperating valve seat according to the movement of the piston 95. Interposed in the piston chamber 9B between the piston 95 and the casing is a spring 04 which yieldingly biases the piston 95 into the position shown, that is in Contact with a stop shoulder |05 wherein a feed or leakage groove H35 is opened around the piston connecting the valve chamber 99 and the piston chamber 95 for equalizing the pressures therein.

The slide valve 02 is provided with a pair of cavities |01 and |08, and a port ||0. In the normal position of the slide valve |02 shown, the Cavity |01 establishes communication between a passage |09, leading to and opening into the pressure chamber 44 of the self-lapping valve device 35, and a passage and the cavity |08 establishes communication between a passage i 2 and an atmospheric exhaust port and passage 3.

Upon a reduction in the safety control pipe pressure and thus in the pressure in piston chamber 95, the higher pressure in slide valve cham.- ber 99 shifts the piston 95 toapplication position in sealing contact with a gasketseat 90, the piston closing the feed groove ||.iny its traverse to application position. In the application position ofthe piston 95, the slide valve |02 is correspondingly positioned in application position so that port ||0 registers with passage and the end of the slide valve uncovers a passage |53 opening at the seat of the slide valve. In application position, the slide valve |02 laps or closes the ports and passages |09 and ||2, and the exhaust port ||3. Y,

The magnet valve casing section 34 has embodied therein a supply magnet valve device I .and a release magnet valve device y| I6. The supply magnet valvedevice ||5 comprises a supply valve l |8which'is contained in a chamber |`|9 that is constantly connected by a passage |22 to a passage anda pipe 2|, hereinafter termed the straight-air pipe. The supply valve ||8 has a fluted stem |23 that extends through a bore |24 into a chamber v|25 into which opens the passage leading from the seat of the slide valve |02 of the emergency Valve device. A spring |26, contained in chamber |25 and acting on the end of the fluted stern |23 through the medium of a collar or flange |21, normally yieldingly urges the supply 4valve 8 into unseated position to open communication between the chamber ||9 and the chamber 25. An electromagnet |28 is effective, whenv energized, to actuate the supply valve 8 into seated position against the force of the spring 20'.

'Ihe release magnet valve device comprises a release valve |3| which is contained in a chamber |32 constantly connected to vthe passage |22 through a passage |33 and a choke |34 having arestrieted passage |35. Abiasing spring |36 disposed in the chamberv |32 and interposed between the release valve |3| and the casing section 34 normally yieldingly `urges the release valve |3| into seated position on a cooperating valve seat. The release'valve i3| has a fluted stem |31 that extends'through a bore |38 in the casing into a chamber |39, into which opens the passage ||2 leading from the seat of the slide-valve |02 of theremergency valve device. An eleetromagnet |42 is effective, when energiZed, to actuate a plunger -|4| to engagethe end of the stem |31 and thereby to shift the release valve |3| away from its valve seat to establish communication from the chamber |32 to the chamber |39.

According to my invention, I provide a safety valve device E45 of well known construction, suitably mounted on the -pipe bracket casing section 3| and subject to the iiuid pressure in the passage ||2. When the exhaust communication of the passage ||2 to the exhaust port ||3, normally established by thercavity |08 in the slide valve |02 of the emergency valve device 40 is cut off in the manner hereinafter described, the safety valve device |45 is eective to release fluid under pressure from the passage ||2 only as long as the pressure of the iiuid exceeds a certain predetermined pressure, the particular pressure being variable according to the adjustment or tension of the loading spring (not shown) of the safety valve Ydevice |45.

Embodied in pipe bracket section 3i is an inshot valve device |48 which comprises a ball valve |49 contained in a chamber 5| that is connected to the seat of the slide valve |02 of the emergency valve device by the passage |53, the passage 53 being lapped at the seat of the slide valve |02 for the normal position of the slide valve as shown. f The inshot valve device |48 kfurther comprises a piston |54 having an upstandingl stem |55 which extends through a passage |56 connecting the chamber |5| and a chamber |51 at one side of the piston |54, the piston |54 being normally yieldingly urged upwardly by a spring |59, which is contained in a chamber |6| at the oppositeside of the piston |54, for causing the stem |55 to engage and unseat the ball Valve |49. 'Ihe straight-air pipe and passage |2| opens into the passage |56 and when the ball valve |49 is unseated, communication is established therepast from the passage |53to the straight-air pipe |2|, this communication being closed when ball valve |49 is seated. Seating of the ball valve |49 is accomplished when the pressure of the uid supplied into the straight-air pipe |2| and effective Vin the passage |56 and chamber |51 on the piston |54 overcornes the pressure of the spring |59 and causes downward shifting of the piston |5.

Referring now to Fig. Al, the controller yvalve device |3, which is of well known construction, comprises a removableV operating handle |1| which is effective upon rotation in a horizontal plane to eifect operative movement of a controller drum for controlling the electrical connections to and the speed of the propelling motor:- of the vehicle or car, in manner not shown, but well understood. 'Ihe operating handle or lever 1|, when inserted in the casing I 12, pivots on a pin |13 and the inner4 bifurcated end |14 thereof straddles a stem |15. When the outer end of the operating handle I1I is depressed, the inner end |14 engages a flange or head at the upper end of the stem |15 and raises the stem |15 against the opposition of a spring |16 interposed between the casing |12 and a nut |11 screwed on the lower threaded end of the stem |15. With the stem |15 raised into the position shown, a double beat valve |18, contained in a chamber I 19 in the casing |12, is actuated by a spring |8I into seated relation on a lower valve seat formed on the casing to close communication between the chamber |19 and an eX- haust port and passage |82, and at the same time to open communication pastthe upper valve seat between chamber |19 and a chamber |83 to which is connected main reservoir pipe 49. A choke |80, screwed to the casing restricts the flow of fluid from chamber |83 to chamber |19 for a purpose hereinafter made apparent.

When the hand of the operator is removed from the outer end of handle I1I or the downward pressure thereon is relieved, spring |16 actuates stem |15 downwardly to rock a pivoted lever |84 in a clockwise direction to shift the double beat valve |18 away from its lower seat and into seated relation on its upper seat, thereby opening the communication from chamber |19 to atmospheric passage |82 and closing the communication between chambers I83 and |19.

The foot-Valve device I4 comprises a suitable casing |86 which is secured lto the floor 92 of the vehicle and which has formed therein a chamber |81, constantly connected to the main reservoir pipe 49 through a branch passage and pipe |88 having a choke |90 therein. The chamber |81 contains a valve |89 of the poppet type which is yieldingly urged by a spring |90, also contained in the chamber |81, into seated relation on an associated valve seat to close communication between the chamber |81 and a chamber |9| to which is connected a pipe and passage 98a. Also formed in the casing |86 is a chamber |92 which is constantly connected to the chamber |19 of the controller valve device I3 by a pipe |93, cornmunication between the chamber |92 and the chamber |9| being controlled by a diaphragm valve |94. Operation of the valve |89 and the diaphragm valve |94 is effected by means of a foot fluted stem |99 of the valve |89 and unseats the `valve |89 against the force of the spring |9|.

Upon the release of the foot pedal |95, the spring |91 shifts it upwardly, and the spring |9| then becomes effective to reseat the valve |89, and through the stem |99 of the valve |89, to unseat the valve |94.

The cut-01T valve device I5 comprises a casing 20| having a chamber 202 and a chamber 203 separated by a wall 204 having a port 205 therein. The chamber 202 is connected to the pipe 98al at one point by a branch pipe 206 and chamber 203 is also connected to the pipe 98a at another point by a branch pipe 201, the section of the pipe 98a between the branch pipes 206 and 201 having a one-way or non-return valve 208 connected therein for preventing the flow of fluid under pressure through the pipe 98a except in a direction indicated by the arrow.-

The cut-off valve device I5 further comprises a diaphragm valve 209 which is normally unseated from the wall 204 to open the port 205 and thus establish connection between the chambers 202 and 203. On the upper face of the diaphragm valve 209 is a follower 2II which is engaged by a follower 2I2 on the lower face of a diaphragm 2I3 which is subject on the upper face thereof to the pressure of fluid in a chamber 2I4 at the upper side of the diaphragm. Formed in the casing 20| is a chamber 2I5 to which the straight-air pipe |2| is connected, communication between the chambers 2I5 and chamber 2I4 through a port 2 I8 being controlled by a valve in the form of a piston Valve 2 I6 which is normally yieldingly urged into seated relation on an associated valve seat by a biasing or loading spring 2|1 to close port 2 I8.

When the pressure supplied to the straight-air pipe |2| and thus to the chamber 2I5 exceeds a certain uniform pressure suiiicient to overcome the spring 2I1, valve 2I6 is unseated from its valve seat and shifted upwardly to contact with an annular gasket seat 2 I9 to close the connection from chamber 2|4 to atmosphere through a passage 22| and port 222. Fluid under pressure supplied from the chamber 2I5 to the chamber 2|4 acts on the upper face of the diaphragm 2 I3 which in turn urges the diaphragm valve 209 downwardly into seated engagement with the wall 204 to Q close the port or passage 205. It will thus be understood that the valve 209 is not actuated to close the port 205 unless and until the pressure in the straight-air pipe |2| and, as will be seen later, also in the brake cylinder I0, exceeds a certain uniform pressure.

When the pressure in the straight-air pipe |2| and chambers 2I5 and 2 I4 reduces below a value suflicient to overcome the spring 2I1, the spring becomes effective to shift the valve 2I6 back to seated position on its associated valve seat, closing the port 2 I8 and opening the exhaust connection for the chamber 2 I4. When the pressure in the chamber 2I4 is thus reduced to atmospheric pressure, the diaphragm 2 I3 returns upwardly and relieves the pressure on the diaphragm valve 209 which accordingly inherently returns to its normal unseated position to open the port 205.

Referring again to Fig. 2, the locking device I6 of the self-lapping valve device 35 comprises a toothed segment 224, which is keyed or otherwise suitably secured to the shaft 19 of the self-lapping valve device 35, and a pawl 225 which is pivotally mounted by a pin 226 on an extension 221 of the casing section 32.

Formed on or attached to the extension 221 is a pressure cylinder 228 containing a piston 229 which is provided with a stem 23| for engaging and rocking the pawl 225 out of engagement with the toothed portion of the segment 224 when uid under pressure is supplied to a chamber 232 at one side of the piston 229. At the opposite side of the piston 229 is a spring 233 which yieldingly opposes the movement of the piston by the pressure of fluid in the chamber 232. Fluid under pressure is supplied to chamber 232 through a pipe 234, hereinafter called the lock pipe, which is connected to the pipe 98a at a suitable point between the non-return valve 208 and the footvalve device I4. When the pressure in the chamber 232 is reduced sufficiently, the yspringr 233 shifts the piston 229 and' its stem 23| in the lefthand direction and another spring 234 which is interposed between extension 221 and the pawl 225y becomes effective to shift the Wpawl 225 into interlocking engagement with the toothed surface of the segment 226.

The teeth of the toothed surface of the segment 224 are so disposed and so constituted that the pawl 225 is effective to hold the segment 224 and consequently the shaft 19 against only counterclockwise rotation, that is, movement toward the normal or release position by the spring 84. Y

Rotation of the segment 224 and shaft 19 in a clockwise direction, that is,v movement corresponding to depression of the brake pedal I2 into the service application Zone, is not prevented.

The retardation controller device |8 shown in Fig. 271sV described in detail and claimed in the copending'application Serial No. 971, ofrClyde C. Farmer, filed January 9, 1935, and assigned to the assignee of the present application and it will accordingly be but briefly described herein. The retardation controller device |8 comprises a suitable casing 24| containing an inertia body 242 in the form of a Weighted pendulum pivotally suspended on a pin 243 attached to the casing 24|. Suitably secured to the lower end of the inertia body 242 is an extension piece 244 which carries, in insulated relation thereon, a contact member 245 which is adapted to engage in succession a pair of stationary insulated contact fingers 246 and 241 which are mounted on the casing 24 The contact member 245 is connected by a wire 248'2to one terminal of a battery 249, shown in Fig. 1, the other terminal of which is grounded. The contact linger 246 is connected by a wire 25| to one terminal of the electromagnet |28 of the supply magnet Valve device ||5 and the contact finger 241 is connected by a wire 252 to oneY terminal of the electromagnet |42 of the release magnet Valve device H6. The remaining terminals of the electromagnets |28 and |48 are connected to the grounded terminal of the battery 249 as by connection to ground at 253.

The retardation controller device I8 is so mounted on the vehicle or train of cars that when the brakes are applied on the vehicle or cars the inertia body 242 swings in the left hand direction against a stop plunger 254. Movement of the stop 254 is yieldingly resisted by a ncoil spring 255 which is interposed between the stop 254 and one face of a piston 256 which operates in a cylinder 251. The stopA plunger 254 has a flange 258 thereon which is adapted to engage a flange 259 on a piston 266 which operates in the bore 26| of a bushing 262 which is screwed into a threaded opening 263 in the casing 24|. A coil spring 264 is interposed between a flange 265 on the bushing 262 and the piston 260 and yieldingly opposes movement of the piston 260 when the flange 258 on the stop plunger 254 engages the flange 259 on the piston 268.

It will thus be seen that the swing of the inertia body 242 in the left-hand direction is accordingly first resisted by the spring 255 alone and then by both the spring 255 and the spring 264. The arrangement ofthe springs 255 and 264 is such that when the inertia force acting on the inertia body 242 is sufficient to overcome only the spring 255, it causes engagement of the contact member 245 only with the vcontact finger 246, and when the inertia force is sufficient to overcome the combined strength of the springs 255 and 264, the inertia body 242 is moved suiliciently in the -left-hand direction to cause f they 2 contact member 245 to engage both the contacty finger 246 and the contact finger 241. Theoperation .of` the retardation controllerv device 8in controlling the vmagnet valve devices H5 and I6 ofthe con# trol valve mechanism will be described in detail hereinafter.

In order to vary the rate of retardation to beY produced on the vehicle or cars as determined by the retardation controller I8, provision ismade for increasing the tension of the spring 255 either manually, by means of a manually operable .ad-- justing device 261, or automatically, by meansof a fluid pressure responsive .device in the form of a piston 268, which is contained iny arpressure cylinder 269 suitably mounted or attached to the casing 24| of the retardationcontroller.

The manually operable adjusting. device v2.61

comprises an operating handle 21| which'ismov able between two Vopposite positions defined by stop members 212 and 213 and designated-fn1inimum and maximum positions. respectively Movement of the operating handle 21| is effective through an operating rod 214 to rotate an operating arm 215 rotatively mounted on a shaft or pin 216 attached to the casing. The hub portion of arm 215 is interlocked with the hub portion of another arm 211 which is also rotatively mounted on shaft 216 and which has a roller 218 at the extremity thereof that engages the outerjface of the piston 256. When they operating handle 21| is in the minimum position in contact with the stop 212, the arm 211 is shifted in a direction away from the piston 256 and thus the spring 255 may expand correspondingly so that a minimum tension is placed thereon. When the operating handle 21| is shifted away from the stop 212 toward the stop 213 the lever arm 211 is moved so as to shift the piston 256 and to compress and increase the tension in the spring 255. When the handle 21| is against the stop 213 correspondingV to the maximum position, the spring 255 is under maximum tension.

The piston 268 is normally subject to the pressure of fluid supplied through the safety control pipe 98 to a chamber 28| at one side of the piston, which pressure overcomes the force of a coil spring 282 at the opposite side of the piston 268. When the pressure in the safety control pipe 98 and thus in the chamber 28| is reduced sufciently, the' spring 282 becornesy effective to shift the piston 268 outwardly. The piston 268 has a stem 284 which is connected through a link 285 to a lever 286 pivoted intermediate the end thereof by a, pin 281 on a lug 288 attached to or formed on the pressure cylinder 251. The opposite end of the lever 286 is connected by a link 289 to the outer end of an operating arm 290 which is rotatively mounted on the shaft 216. vThe hub of the arm 290 is interlocked with thehub of the arm 211 in such manner as to cause rotation of the arm 211 to increase the tension of the spring 255. When the piston 268 is shifted outwardly by the reduction of the pressure of the fluid inthe chamber 28| and in the'safety control pipe 98, the lever 286 is rocked in a counterclockwise direction to cause movement of the lever arm 211 to increase the tension of the spring 255 to the fullest extent corresponding to that produced when the operating handle 21| of the manually operable adjusting device 261 is in the maximum position against the stop 213.

l The hub portions ofthe operating arms 215, 211 and 296 are so constructed and interlockingly arranged that movement of the operating han'- dle 21| of the vmanual adjusting device 261 is inieffective to cause movement of the piston 268, and that shifting of the piston 268 is ineffective to shift the position of the operating handle 21|.

A spring biased stop 29| disposed at the opposite side of the inertia body 242 to the stop plunger 254 serves to limit the movement of the inertia body 242 in the right hand direction and also to normally hold the inertia body 242 against undesirable movement and vibration resulting in undesired engagement of the contact member.

245 with the contact members 246 and 241.

Referring now to Fig. 1, the anti-wheel sliding device I9, shown in Fig. 1,.is substantially the same as that shown, described and claimed in the copending application Serial No. 713,103 of Rankin J. Bush, led February 27, 1934, and aS- signed to the assignee of the present application and will therefore be .described only generally herein. The device I9 comprises a suitable casing 36| having a shaft 362 supported for rotation atopposite ends thereof in suitable journals in the casing 36|,fthe shaft 362 being driven in any suitable manner, as through connecting j gears, according to the speed of rotation of a wheel or an axle of thev vehicle or car.

Mounted' on the shaft 362, as by suitable ball or roller bearings 364, is an inertia body 365 in the form of a fly-wheel. The inertia body 335 is resiliently connected to the shaft 362 and driven thereby through the medium of four spring pressed plungers or stops 366 carried on and attached'to the inertia body, two of which are on one side and two of which are on the opposite side of a rod 361 secured to the shaft 362 and extending at right angles to the longitudinal axis of the shaft 362.

Also mounted on the shaft 362 in axially displaced relation to the inertia body 365 is a wheel or disc-368 having ahub 369. Apin 3I6, extending transversely through the hub 369 of the wheel 366 and through a transverse slot 3|I in the shaft 362-, secures the wheel 368 to the shaft 362 for rotation therewith.

Mounted in suitable recesses at the periphery ofthe wheel 368 on pins 3I2 are a plurality of rollers 343 which are adapted to engage in V- shaped recesses 3| 4 that are formed in an annular rib 3I5 at o-ne end of the inertia body 365. A coil spring 366, interposed between a shoulder 3i6 on the hub 369 of the wheel 368 and a suitable adjusting nut 3| 1 screwed over a threaded portion 3|8 on the shaft 362, yieldingly urges the wheel 363 in the direction of the inertia body 365 and tends to maintain the rollers 3| 3 engaged in the recesses 3I4 on the inertia body 365.

Slidably mounted in a longitudinal bore 32| opening at the free end of the shaft 362 is a plunger rod 322, the inner end of which has a transverse hole 3.23 through which the pin 3|6 extends. It will thus be apparent that the plunger 322 and the wheel 368 move together.

A switch arm or lever 324 is pivotally mounted intermediate the -ends thereof on a pin 325 attached to a lug 326 on the casing 36| and is rocked on the pin 325 by shifting of the plunger 322 outwardly of the bore 32|. The switch arm 324 has a contact bridging member 321 mounted in insulated relation thereon for connecting a pair of stationary insulated contact fingers 328 and 329 when the plunger 322 moves outwardly of the bore 32% tol rock the switch arm 324 in a counterc'lockwise direction. Y

When-the brakes are applied on the axle from which the shaft 362 is driven, the vinertia of the inertia body 365 'overcomes the force of the spring biased stops 366 and moves relatively to the shaft y362. Due to the fact that the wheel 368 moves at the same speed as the shaft 362, the sloping side surfaces of recesses 3I4 on the inertia body 365 act as cams to force the wheel 368 ,axially along the shaft 362 in opposition to the tension of the spring 366. The plunger 322 is accordingly correspondingly shifted outwardly of borev 32| so as to rock the switch arm 324 towards the contact fingers 326 and 329. If the movement of the inertia body 365 relative to the shaft 362 is sufficient, as when the axle and associated wheels start to slip or reduce rapidly y to Zero speed, the rollers 3|3 ride up out of the recesses 314 tothe outer face of the annular rib 3i5. Suicient shifting of the wheel 368 and the plunger 322 is thus produced to cause the switch arm 324 to bridge the contact members 328 and 329 in circuit-closing relation.

When the shaft 362 and wheel 368 over-speed the fly-wheel inertia body 365, as when the train wheels accelerate back toward a rotative speed corresponding to the speed of the train following slipping thereof, the relative movement between the wheel 368 and body 365 also results in engagement of the switch arm with the contact members 328 and 329 in circuit-closing relation.

The control valve device 2I comprises a casing 335 having a chamber 336 which is connected to the straight-air pipe I2I through a branch pipe and passage 331, an air-strainer device 338 being interposed between the passage 331 and the chamber 336. Also formed in the casing 335 is a chamber 339 which is constantly connected to the brake cylinder i6 through a pipe and passage 34I. The chamber 339 contains a pair of oppositely seating valves 342 and 343, the valve 342 being effective to control communication between the chamber 336 and the chamber 339 and the valve 343 being effective to control the communication between the chamber 339 and a chamber 344 which is constantly open to the atmosphere through a port 345. A spring 346 acting on the valve 342 normally yieldingly urges the valves 342 and 343 into unseated and seated positions respectively to open the communication between the chamber 336 and the chamber 339 connected to the brake cylinder I6 and to close the communication between the chamber 339 and the atmospheric chamber 344.

A piston 348 operates in a bore 349 in the casing, the piston being subject to the pressure in v the atmospheric chamber 344 on one side thereofand to the pressure in a chamber 35| at the other side thereof. The piston is provided with a stem 352 having a bore 353 therein containing a spring biased stop 354 which is adapted to engage the uted stem of the valve 343.

When fluid under pressure is supplied to the chamber 35|, the piston 348 is urged upwardly to unseat the valve 343 and to seat the valve 342, communication between the chamber 336 and the chamber 339 connected to the brake cylinder I6 being thus cut oi or closed and communication between the chamber 339 and the atmospheric chambers 334 being opened.

The magnet valve device 26 controls the supply and the release of fluid under pressure to and from the chamber 35| of the control valve device 2|. The magnet valve device 26 comprises a pair of oppositely seating valves 356 and 351, the valves having fluted stems which meet in end- Cil tol-end contact in a chamber 358 Whch'is Yconstantly connected to the chamber 35| of the control valve device 2| by a pipe and passage 359. The valve 35S is contained in a chamber 36| which is constantly open to atmosphere through a port 362, and the valve 351 is contained in a chamber 363 which is constantly connected to the main reservoir pipe 49 by a branch pipe 364 and another branch pipe 365. A coil spring 366 con-V tained in chamber 3673 and acting on the valve 351 normallyfrurges the valves 356 and 351 into seated and unseated positions, respectively, the valve 356 establishing communication from the chamber 358'to the atmospheric chamber 376| .if and tffne valve351 closing communication between the chamber Y358 and the chamber 363,' An electromagnet 361 is effective, when energized, to actuate a plunger 368 which engages the valve 356 in the chamber 36| to shift the valves 356 and 351, against the opposition of the spring 366, into seated and unseated positions, respectively, the valve 35 thus closing the communication between the diamber 358 and the atmospheric chamber 36| and the valve 351 opening the: cemmunication between the chamber 358 and Yrthe chamber 363.V

One terminal of the electromagnet 361 is connected by a wire 31| tothe contact finger 329 of the anti-wheel-sliding device I9, and the opposite terminal of the electromagnet 361 is connected to the grounded terminal of the battery 249 as by connection to ground by a wire312. The contactlnger 328 is connected by a wireY 313 to the wire'248 which is connected, to the nongronnded terminal of the battery @1249. It will thus be seen that when the switch* arm 324 of the anti-wheel-sliding device I9 is actuated into circuit-closing position connecting the Contact fingers 328 and 3219, the circuit isV established for energizing the electromagnet 361 of the magnet valve device 20.

The ventvalve device 22 comprises a casing 316 which is attached to the floor 92 of the Vehicle or ncontrolcar and which has a Ychamber 311 therein to which the pipe 98a is constantly connected. The chamber 311gcontainsV a Valve 318 which is normally yieldingllr urged by a spring 380 into seated relation on an annular ribY seat 319 to close a portj38| through which uid under pressure in the chamber 311 may be exhausted toY atmosphere. The valve 318 has a stern 382 which extends through the port 38| to thegfupper surface of the iioor 92 and whichis adapted to be engaged by .a lug 383 on the under surface of the brake pedal I2 only when the brake pedal I2 is fully depressed. When the brake pedal I2 is fully depressed into the emergency position indicated, the valve v318 isunseated to exhaust fluid under pressure from the chamber31'1 and accordingly from the pipe 98a and the safety control pipe 498. The magnetic track shoe brake Vdevice 231 may comprise a shoe portion 386 which is adapted 'to engage the track Yrail 381, a magnetic core portion 388 and an electrpmagnet winding 389 mounted in insulated relation in associated relation with the reagnet core 388.

Movement of the magnetic track brake shoeVY device I9 into and outfofcont'act with the track?Y rail 381 is effected in any suitable manner, `as byn means of a pressure cylinder i391 suitably rnounti ed on -or secured `to a portion of the vehicle truck 392. The pressure cylinder39l contains a ,piston 393 havinga' stem 394 Vonwhichr the V "magng-'ztic track brake shoek device '29 may be suspended by lmeans of' an inverted U-shaped bracket 39.5 pivotally connected centrally ofthe legs thereof to the outer end of the stem 394, the track brake shoe device 23 beingv secured to the Youter end of the legs of the bracket 395.' At onje side of the piston 393 is a chamber 396 to which fluid under pressure is Ysupplied and from which fluid under pressure is releasedunder the control of the mag-V net valve device 24,5; A biasing spring 391 acting on the side of the Ypiston opposite tothe chamber 396 is :effective when liuid under pressure is released from the chamber 396 to urge the piston 39; downwardly so that', assisted by gravity, the track brake shoe device 23 dropsiY into contact with the track rail 381. f

IThe magnet valve device24 comprises a casing having a chamber 399 which is constantly connected to the chamber 396 of the pressure cylinder 39| by a pipe OI. Contained in the lchamber 399 are a pair of oppositely seating valves 402 and 403. :The valve 402controls communication from the chamber399 toa chamber 404 which is constantly connected to atmosphere through a port 405 and the valve 403 controls communication between the chamber 399 and a chamber 406 which is connected bythe pipes 365 and 364 tothe main reservoir pipe49. A spring 401 contained in the chamber 406Y and acting on the end ofthe fluted stern of the VValve'403 normally l yieldinglyurges the valves 402 and 403 into seated i;

and unseated positions respectively, the valve 402 closing the communication between the chamber 399 and the chamber 404 and the valve 403 Y opening the communication between the chamber 399 and the chamber 406 connected to the main reservoir pipe 49.

The magnet valve device 324 further comprises an electrcmagnet 409 which when energized actuates a plunger 4|0 to engage the endg; of thei'luted stem of the valve 402 and shifts the valves 402 and'403 against the force of the spring Y 401 into unseated and seated positions respec-Y the electromagnet 409 ofthe magnet valve device,V 24 is deenergized, uid under pressure is'rsupplied under the control of the magnet valve device 24 to the chamber396 of the pressure cylinder 39| to raisethe track shoeVV brake device 23 out of contact'with the track ,grail 381.` It will also be apparent that when'theelectro'magnet 409 of the magnet valve 4device 24 is energized, fluid under pressure is released from the pressure chamber` 396-and the trackfbrake shoe 23 accordingly falle intol Contact with the track rail 381. l Energization and deenergization of the electro; magnet 389 of the magnetic track brake shoe device 23 and the electromagnet 409 `of the magnet valve device 24 is effected under the/controlY of the controller device 25 in the manner to be presently described. v

Referring to Figs. r2 and 5, the controller device 25 comprises a casing 4I which is adapted to be mounted in any suitable manner and which may be attached to the self-lapping valve casing section 32 of the controlvalve meehanism II. Cori- H tained within the casing 25 is a controller drum 4 I 2 of insulating material which may be mounted for rotation in the casing in any suitable manner, as on a shaftil4|3 journaled at its opposite ends to the casing 4II and having secured'thereto a pinion gear 4 |4. Inset in the surface of the drum is a stepped contact segment 4|5.

Associated with the controller drum 4|2 are a plurality of contact fingers 4|1 to 425 which are mounted in insulated relation on the casing 4| I and arranged in spaced relation longitudinally of the drum 4|2 and suitably biased as by springs 426 into contact with the surface of the drum 4|2. As indicated in Fig. 5 and Fig. 2, the contact finger 4|1 is constantly connected to a source of electric current, such as a trolley wire 421, as by a Wire 428 and the trolley pole 429.

The contact finger 4|8 is constantly connected to one terminal of the electromagnet 469 of the magnet valve device 24 as by wires 43|) and 43|, the opposite terminal of the electromagnet 469 being connected to ground by a wire 432.

The contact finger 4| 9 is connected to one terminal of a resistor 434. The opposite terminal of the resistor 434 is connected by a wire 435 and a branch wire 433 to one terminal of the electromagnet 389 of the track shoe device 23, and the opposite terminal of electromagnet 389 is connected to ground by a wire 436.

The contact fingers 420, 42|, 422, 423, 424 -and 425 are connected to successive points along the resistor 434, the contact nger 425 being connected to the terminal of the resistor 434 to which the wire 435 is connected.

When the controller drum 4|2 is rotated in a counterclockwise direction, as viewed in Fig. 2, the contact segment 4|5 rst connects the contact fingers 4|1, 4|8 and 4|9, thus establishing circuits for energizing the electromagnet 409 of the magnet valve device 24 and for energizing the electromagnet 389 of the track shoe brake device 23. As the controller drum 4|2 continues to rotate in a counterclockwise direction, the contact ngers 42D, 42|, 422, 423, 424 and 425 are Asuccessively engaged by the contact segment 4|5 to cause a successively increasing amount of the resistor 434 to be shunted and thus increasing in steps, correspondingly, the current supplied from the trolley Wire 421 through the resistor 434 to the electromagnet 389 of the track brake device 23 to increase the excitation thereof and accordingly the degree of braking force effected thereby. t

Rotation of the controller drum 4|2 is effected by means of a gear segment 438 which meshes with the pinion gear 4|4 on the shaft 4|3 of the controller drum 4|2, the gear segment 438 having a hub portion 431 suitably journaled for rotation on a shaft 19a which is suitably supported for rotation in the casing 4| 19a may be coupled directly to the shaft 19 of the self-lapping valve device 35, as indicated by the broken line 449 in Fig. 2, or may be connected in any suitable manner to rotate in' accordance with the rotation of the shaft 19. Se-

cured to the shaft 19a adjacent the hub 431 of gear segment 438 is an operating arm 439 which carries an adjusting screw 44| that is positioned in the plane of the gear segment 438 and which is adapted to engage the segment to move it in accordance with the rotation of the shaft 19a and arm 439. A coil spring 442 is secured at one end to a lug or pin 443 on the gear segment 438 and at the oppositevend to a lug 444 on the casing 4|| and thus normally yieldingly biases the gear segment 438 to rotate in a counterclockwise direction, as viewed in Fig. 2, to cause rotation of the controller drum 4|2 in a clockwise direction to the normal position shown, wherein the said contact segment 4|5 disengages all of the contact The shaft ngers 4|1 to 425. A projecting lug 446 on the gear segment 438 engages a stop lug 441 formed on the casing 4|| to limit the rotation of the gear segment 438 in the counterclockwise direction and thus determine the normal position of the controller drum 4|2.

It will accordingly be apparent that since the shaft `19 of the self-lapping valve device 35 is operatively rotated by depressing the brake pedal I2 and since the shaft 19a of the controller is so connected to the shaft 19 as to rotate therewith, the depression of the brake pedal |2 causes simultaneous operation of the self-lapping valve device 35 and of the controller device 25, the selflapping valve device 35 functioning to effect application of the fluid pressure brakes and the controller device 25 functioning to effect application of the magnetic track shoe brakes in the manner to be hereinafter described.

The pneumatic switch 26, as illustratively shown, may comprise a casing containing a piston 45| having a stem 452 carrying in insulated relation thereon a pair of spaced contact bridging members 453 and 454 for connecting, respectively, a pair of insulated stationary contact fingers 455 and a pair of contact fingers 456.

At one side of the piston 45| is a chamber 451 which is constantly connected to and charged with iiuid under pressure from the safety control pipe 98 through a branch pipe 459. At the opposite side of the piston 45| is a chamber 46| containing a compression spring 462 which lis interposed between the piston 45| and the casing so as to yieldingly urge the piston in the left hand direction, as Viewed in Fig. l, to cause the contact bridging members 453 and 454 to engage their respectively associated pairs of contact fingers 455 and 456 in circuit-closing relation. When chamber 46| is charged with fluid under pressure, the piston is shifted against the force of spring 462, to effect disengagement of the contact bridging members 453 and 454 from their respectively associated contact fingers 455 and 456.

One of the contact fingers 455 and one of the contact lingers 456 are connected together and to a source of current, such as the trolley wire 421, by a wire 463. The other of the contact fingers 455 has the wire 435 connected thereto and is thus connected by the branch wire 433 to one terminal of the electromagnet 339 on the track shoe device 23. The other of the contact fingers 456 is connected by the wire 43| to one terminal of the electromagnet 469 of magnet valve device 24.

It will thus be apparent that the pneumatic switch device 26 is eifective, when the pressure in the safety control pipe 98 and thus in chamber 451 is reduced sufficiently, to complete circuits independently of the controller 25, for energizing the electromagnet 389 of the track shoe device 23 and for causing magnet valve device 24 to be actuated to release uid under pressure from chamber 396 of the pressure cylinder 39| and thus cause the track shoe device 23 to be lowered into contact with the track rail 331.

It will be understood that the pneumatic switch device 26 is merely illustrative of any suitable circuit controlling device controlled by variations in pressure'in the safety control pipe 98.

Operation of equipment f|1|y of the control valve device lI3 being depressed, iiuidunder pressure is supplied from the main reservoir 3 to the safety control pipe 98 and the lock pipe 234 through the branch pipe` 5| and main reservoir supply pipe 40, cham.- ber |83 of the controller valve device |13 past the upper open valve seat of the valve |18, charnber |19, pipe |33, chamber |92 of the foot-valve device I4, past the unseated diaphragm valve |94, chamber |9| and pipe and passage 38d. The chamber 232 of the pressure cylinder 228 of the locking device l5 is supplied with fluid under pressure from the lock pipe 234 and piston 229 is accordingly actuated to disengage the pawl 225 from the toothed segment 224.# Fluid under pressure is supplied from the safety control pipe to chamber 451 of pneumatic switch device 25, the piston chamber 95 of the emergency valve device 40 and piston chamber 28| of the retardatrack brake shoe device 23 out of contact withthe rail 381. l

Since the switch arm 324 vof the anti-wheelsliding device is in open position, the magnet valve device 20 is effective to vent the chamber of the control valve device 2| and thus the brake cylinder l0 is connected to the straightair pipe |2| which is connected to the pressure chamber 4,4 of the self-lapping valve device 35 through passage |22, chamber ||9 of the supply magnet valve `device H5, bore |24, chamber |25, passage cavity |01 in the slide valve |02 of the emergency valve` device 40, and passage |09. Since the pressure chamber 44 is vented to atmosphere, the straight-air pipe |2| is thus also vented to atmosphere. Fluid under pressure is, accordingly, entirely released from the brake cylinder l0 and other brake cylinders, not shown, soy that the. fluid pressure brakes are released. Furthermore, with the pressure' in the chamber 2|5 at atmospheric pressure due to the pressure in the straight-air pipe being at atmospheric pressure, the valve 2|6 of the cut-off valve device l5 is seated on'its lo-vver seat and unseated from its upper gasket seat 2 I9 to vent the chamber 2|4 soI that the diaphragm valve 209 is accordingly unseated to open the by-pass communication around the non-return valve 208 in the pipe. 98a

ythrough pipe 205, chamber 202 of the cut-off valve device l5, port 205, chamber 203 and pipe 201.

(b). Service application 'of the brusca-Assuming that the vehicle or train of cars is traveling along the road with the equipment conditioned as shown in Figs. 1 and 2, and that it is desired to effect a service application of the brakes, the operator rst shifts Athe operating .handle |1| of the controller valve .device I3 to zvalve Ydevice 35 causes fluid underr .pressure to be supplied from the main reservoir 9 .to the straight-air pipe |2| through the pressure chamber 44, passage |09, cavity |01 of the slide valve A|52 of the emergency valve device 40, passage ill, chamber |25 of the supply magnet valve device H5, bore |24, chamber H9, and passage |22. Fluid under pressure is accordingly supplied to the brake cylinder l0 from the straightair pipe `|2| past the unseated valve 342 of the control valve device 2| and to! the rchamber 2| 5 ol the cut-01T Valve device 5.

Simultaneously with the initiation of Ythe application of the fluid pressure brakesv bythe supply of fluid under pressure to the brake cylinder l0, the contact segment 4|5 on thev controller drum 4|2 connects the contact fingers 4|1, 4| 8, 4|9, to. cause initial energization of the'electromagnet 339 of the track brake shoe device 23 and the lowering of the track' brake device 23 Ainto contact with the rail 331 in the manner previously described.

By `further depressing the brake pedal l2 into the service application zone, the pressure of iluid supplied to the straight-air pipe |2| and to the vbrake cylinder l0 is increased. Simultaneously,

the rotation of the controller drum 4|2 successively shunts portions of theV resistor 434 and thus causes an increase in the degree of excitation of the electromagnet 380 of the track brake device 23, whereby the' degree of application of the magnetic track shoe brakes is increased.V

A full service application Vof the brakes is obtained when the lug 383 on the underside of the brake pedal l2 just engages the stem 382 of the vent valve 22 without unseating Athe valve 318. Since the spring 380 holding the valve 318 of the vent valve 22 seated necessitates an additional increase 'in the force required to further depress the brake pedal I2, the operator is: informed sensitively that he has reached the limit of the-service application zone. Y

VThe pressure established in the pressure chamber 44 of the self-lapping valve device 35 is in proportion to the degree or the amount of movement of the brake pedal into the service application Zone and as long asthe rate of retardation of the vehicle Yor train of cars resulting from the simultaneous application of the magnetic track shoe brake 23 and the fluid pressure brake does not exceed the settingof the retardation controller i3 as determined by the manually operable adjustingdevice 261, the pressure in the straight-air pipe 2| and in the brakecylinder |0 corresponds to the pressure in theY pressure chamber 44. However, if the rate of retardation of the vehicle exceeds the setting of the retardation controller i8 and the inertia body 242 is `actuated to cause the movable contact member 245 carried by the inertia body to engage lthe contact nger 246, the circuit is completed for energizing the electromagnet |28 of the supply magnet valve device H5 to actuate the valve 8 to close off the connection between the pressure chamber 44 and the straight-air pipe |2|, so that further Vincrease in the pressure in the straight air pipe is prevented. v

When the rate of retardation of vthe vehicle further increases, due to the increase inY the coefficient of friction between the rubbing partsof the nuid pressure brakeand also between thet" magnetic track shoe 23 and the rail 38-1 caused by reduction in speed of the vehicle, the inertia rbody 2&2 is swung further to the left so that the contact member 245 contacts the Contact finger 241 as wellas the rcontact finger `246.l The electromagnet |42 of the release magnet valve device IIB is accordingly energized and the release valve I3I unseated to open communication from the straight-air pipe I2I to the exhaust port I I3 of the emergency valve device 40 through passage |22, restricted passage |35 of the choke |34, passage |33, chamber I32 past the unseated valve I3I, bore |38, chamber |39, passage II2, and cavity |88 in the slide valve |82.

The degree of brake cylinder pressure is accordingly reduced until the rate of retardation of the vehicle or train of cars due to the combined effect of the magnetic track shoe brakes and the fluid pressure brakes is insuflicient to maintain the contact member 245 of the retardation controller device I5 in contact with the contact member 241, whereupon the circuit for energizing the electromagnet |42 of the release magnet valve device H6 is interrupted and the release valve ISI reseated to close oi the communication, just described, through which fluid under pressure was exhausted to atmosphere from the straight-air pipe I2I.

It will thus be apparent that the degree of application of the fluid pressure brake is automatically controlled by the retardation controller device I8 so as to supplement the braking effect caused or produced by the magnetic track shoe brake suniciently to produce the rate of retardation as determined by the setting of the adjusting handle 21| of the adjusting device 261 and accordingly of the retardation controller I8.

If for any reason, as for example the temporary condition of the track rails, the braking force applying the brake shoes to the wheels on an individual axle is great enough that the wheels begin to slip, that is, decrease in speed of rotation from that corresponding to the speed of the vehicle toward zero speed corresponding to the locked position of the wheel, the anti-wheel sliding device I9 functions immediately to close the circuit for energizing the electromagnet 331 of theV magnet valve device 20. rThe magnet valve device 28 is accordingly actuated to cause fluid under pressure to be immediately and rapidly supplied to the chamber 35| of the control valve device 2|. The piston 348 of control valve device 2| is thus actuated to cause the connection from the straight-air pipe I2I to the brake cylinder I to be closed and to cause the brake cylinder II) to be connected to the atmospheric chamber 344 to exhaust fluid under pressure therefrom.

The magnet valve device 2|] is mounted close to the control valve device 2| so that the pipe 359 is of relatively short length, and the control valve device 2| is mounted close to the brake cylinder I0 so that the connecting pipe l34| therebetween is relatively short in length. Thus upon the energization of the magnet valve device 28 the control valve device 2| is substantially immediately operated to vent fluid under pressure from the brake cylinder I0 and reduce the degree of application of the fluid pressurebrakes. In view of the fact that the anti-wheel-sliding device IS responds quickly to the tendency of the wheels to slow up to a locked condition due to the application of excessive braking force thereon, the switch arm 324 is actuated to circuit-closing position to energize the magnet valve device 2D and thus effect release of fluid under pressure from the brake cylinder ID while the wheels are slipping, that is reducing from train speed to zero speed, and before the vehicle Wheel or wheels actually reach a locked condition.

Due to the rapid reduction in the pressure of the fluid in the brake cylinder Ill associated with the axle and wheel unit tending to approach a locked condition, the braking force of the fluid pressure brakes acting on the wheels and axle is rapidly reduced and thus the axle and wheel unit again returns towards the speed corresponding to the speed of travel of the vehicle. The switch arm 324 is held in circuit-closing position while the slipping wheels accelerate and is returned to the circuit-opening position when the slipping wheels again rotate at a speed corresponding substantially to train speed. When switch arm 324 returns to circuit-opening position, the magnet valve device 20 is deenergized to cause operation of the control valve device 2| to restore the connection ofthe brake cylinder Ill to the straightair pipe `|2I and cut off the connection from the brake cylinder I8 to atmosphere through the exhaust chamber 344 and port 345.

If the braking force applied to the axle and wheel unit by restoration of pressure in the brake cylinder I8 is still excessive, the operation is repeated, so that at no time are the individual wheels and axle units permitted to attain a locked position. Sliding of the Wheels along the track rails on one spot on the wheel is thus prevented and, accordingly, the development of flat spots on the Wheels is prevented.

It will be noted that the control valve device 2| is actuated to cut off the connection between the straight-air pipe I2I and the brake cylinder IG. Thus the pressure in other brake cylinders (not shown) as determined by the pressure in the straight-air pipe I2I is unaffected by the operation of the anti-wheel-sliding device IS for the brake cylinder I!! shown. Since each brake cylinder is thus individually controlled by an anti-wheel-sliding device corresponding to the device I9 shown, it will be seen that the pressure in all brake cylinders is not necessarily simultaneously reduced upon the tendency of one wheel-and-axle unit to slide. Economy of uid pressure consumption is thus obtained..

(c). Release of the brakes following a service application- In order to effect the release of the brakes after effecting a service application thereof in the manner previously described, the operator merely relieves the pressure applied to the brake pedal I2 to permit it to return upwardly toward its normal raised position. The shaft 19 of the self-lapping valve device 35 and the shaft 19a of the controller device 25 are accordingly returned toward the normal position thereof, the self-lapping valve device 35 correspondingly functioning to reduce the pressure in the pressure chamber 44 and in the straight-air pipe i2I and the controller device 25 functioning to successively cut in portions of the resistor 434 to decrease the exciting current for the electromagnet 389 of the magnetic track shoe device 23.

Upon the complete release of pressure from the brake pedal I2, and its return to its normal raised position as shown in Fig. l, the selflapping valve 35 is conditioned to vent the pressure chamber 44 and the straight-air pipe I2I to atmosphere and the drum 4I2 of the controller device 25 is returned to the position shown in Fig. wherein the circuits for energizing the magnet valve device 24 and the electromagnet 389 carried on the magnetic track brake shoe device 23 are interrupted. Since the brake cylinder I8 is connected to the straight-air pipe I2I past the unseated valve 342 of the control valve device 2l, fluid under pressure is vented therefrom simultaneously with the venting of lluid under pressure from the straight-air pipe |21, and the fluid pressure brakes arethus completely released. Uponthe deenergization of the magnet valve device 24, fluid under pressure is again supplied to the chamber 396 of the pressure.

cylinder 39| and the magnetic track shoe brake device l23 is accordingly raised out of contact with the track rails 381. i

(d). Manual emergencyapplicationg of the brakes-If it is desired to effect an emergency application of the brakes manually, this may be accomplished by the ful-l depression of the brake pedall I2 through the service application zone to the emergency position, which is the limit of movement of the brake pedal toward the oor 92. the emergency position of the brake pedal I2', theY valve 318 of the vent valve 22 is unseated and the pressure `in the pipe 98a and in the safetycontrol pipe 98ris reduced because the choke |99 in the controller valve device I3; restricts the now of fluid under pressure from the main-.reservoir supply pipe 49 to the pipe 98a. and the safety control pipe 98 to a rate which is less than the rate at which-the fluid under pressure is vented past the unseated valve 318 of the vent valve device 22'. i

In the event that the pedal |95 of the footvalve device i4 had been depressed and then raised with the controller handle I1I in its raised position, the choke |99 in the :passage |88 of the foot-valve device I4 would function similarly to restrict the rate of flew of fluid under pressure from the main reservoir supply pipe 49 to the pipe 98a andzethe safety control pipe 98, so that the unseating: of the valve 318 would effect the reduction in the' pressure in the safety control pipe 98. i if Upon the reductionl in the pressure of the fluid in the safety control pipe 98 eifected by operation of the brake pedal. I2 in the manner just described, the piston 95 of the emergency vaive device 49 is shifted by the higher main reservoir pressure in the valve chamber 99 downwardly frorn the normal position thereof into contact with a gasket seat 99v after first closing the feed groove |96 to close off the connection between the valve chamber 99 and the piston chamber 96. At the same time, reduction of pressure in chamber 451- of pneumatic switchgdevice 26 and inthe chamber 28| of thepressure cylinder 269 of the retardation controller devicerl is effected by the reduction ir; the pressure in the safety control pipe 98. As a result, the pneumatic switch device 26 is actuated tocircuit-closing position to effect application gf the magnetic track shoe device 23- to maximum degree and the pistonr268 of retardation controller device I8 Yis shifted by the force of the spring 282 outwardly of the pressure cylinder 269 te cause the lever arm 211 to actuate the piston 256 to increase the tension on the springA 255 to the maximum extent.

At the same time also, the reduction in the saiety control pipe pressure causes a reduction infthe pressure in the lock pipe 234 anda consequent actuation of the pawl 225 of the locking device I6 into engagement with the toothed surface on the segment 224,;fluidfunder pressure being Vented fromthe lock pipe 234, in parallel through the cut-oir valve device I and thev nonreturn valve 298,:-to atmosphere past the unseated valre 318 of the vent valve 22.

Ihe actuation ofv the pawl 225 into engagement with the toothed segment 224 is without effect atl this time, except to prevent the return of the brake pedal I2 to its normal raised position, as will be described and explained hereinafter.

Upon the gshifting of the piston 95 of the emergency valve device 49 to application position,;;the slide valve |92 is likewise shiftedto application position wherein the port: |I9 in the slide valve |92 registers with the passage III and the passage |53 is uncevered, the exhaust port and passage II3 and the passage |99 and |2 being lapped or ciosed at the seatzf the slide valve |92. Fluid under pressure is accordingly supplied from the main reservoir 9 to the straight-air pipe |2 through branch pipe 5I, main reservoir supply pipe and passage 49, passage |9I, and valve chamber-99 of the emergency valve device, whence'it-flows through two parallel paths, the one being through the `passage |53, chamber I5I of the inshot valve device |48, past the unseated ball valve |45, and through `the passage |56, and the other path being` through the port |||1 in thezslide valve |92, passage III, chamber |23 of the supply magnet valve device II3, Abore |124, pastf the uns-cated supply valve IIB; chamber ||9, and passage |22. f

In the same manner as previously described fora service application of the braises, the controller device 25 is operated-simultaneously with the operation of the self-lapping valve device 35 by operation orY the brake pedal I2, but in view of the fact that the pneumatic switch device 26 has operated, as previously described, to cause the magnetic track shoe brake device 23gto be lowered into Contact with the track rail and to cause the electromagnet 389 of the track shoe brake device to be energized, the operation of the controller 25 is without efect except to establish circuits in parallel with those established by thepneumatic switch device 26.

When the pressure of the uid supplied from the main reservoir-*9 to the straight-air pipe I2I and brake-,g cylinder I9 is sufficient to overcome the tension ofV the-spring |59 of the inshotrvalve device |48, the piston |54 is shifted downwardly and, with-the consequent lowering of the stem |55 on the piston |54, the ball valve |49 is seated to-cut oi the further supply of fluid under pressure to the straight-airpipe I2! and to the brake cylinder I9: through the path controlled by the inshot valve device. Fluid under pressure continues to flow to the straight-air pipe and the brake; cylinder I9 through the other parallel path, under the control of the supply magnet valve device II5, as long as the retardation controller device I8 is not operated to effect energzation of theA electromagnet I28=of the magnet valve device I I5 and the consequent seating of the supply valve ||8 to ciose the communication to the straight-air pipe. i .Y

The purpose or"Y the inshot valve device |48 is Y thus to insure a build up of pressure in the straight-air pipeV |2| and in the brake cylinder which isY adequate to produce sufcient braking force onnthe vehicle wheels to bringv the car or train of cars to. a stop yet which will not cause sliding of the wheels. YYYObviously, but for the provision of theI communicationcfrom the main reservoir to the ,.-straightl-air pipe which is controlled by the inshot valve device 248, the accidental sticking of the supply valve I|8 in closed position, such as might be caused due te break- Ying of the biasing spring |26 which acts to unseat the valve 8, operation or the emergency valve device 49 would otherwisegbe ineffective to producean application-of the brakes. By thus providing two parallel communications, under the control of the emergency valve device 4|), through which fluid under pressure is supplied to the straight-air pipe, and by providing the inshot valve device |48 to prevent the excessive build up of pressure in the straight-air pipe in the event that fluid under pressure is supplied to the straight air pipe through only the communication controlled by the inshot valve device due to accidental sticking of the supply valve H8 of supply magnet valve device l5 in closed position, application of the brakes by operation of the emergency valve device 4U in a safe manner without excessive braking force or shock to the cars is assured.

Assuming that the supply magnet valve device ||5 is in good condition and functions properly, the retardation controller device |8 is effective during emergency applications of the brakes to cause, first, closing of the supply valve H8 and then, as the speed of the car or train decreases, unseating of the release valve |3| of the release magnet valve device H6. In view of the fact that the pressure in the chamber 28| of pressure cylinder 29 has been reduced by reduction in the pressure of the safety control pipe 98, the retardation controller device |8 is set so as to produce a maximum rate of retardation. Consequently, since the tension on the spring 255 of the retardation controller I8 has been increased to the 'maximum degree, the contact member 245 carried by the inertia body 242 of the retardation controller device IS is not swung into contact with the contact finger 246 until the pressure bulit up in the straight-air pipe |2| and the brake cylinder l@ produces sufficiently high braking force to overcome the increased degree of tensioning of the spring 255.

It will be apparent that since the tension of the spring 264 of the retardation controller device remains constant and is not effected by reduction in pressure in the chamber 28| of the pressure cylinder 269, the amount of the difference in braking force required to cause contact of the contact member 245 only with the contact finger 246 and that required to cause contact also with the Contact finger 24? is a constant value, and accordingly that the pressure in the straight-air pipe |2|, as controlled by the retardation controller device I8, corresponds substantially to the degree of tensioning of the spring 255.

It will also be apparent that due to the fact that the slide valve |02 of the emergency valve -device 40, when in application position, laps or closes the exhaust port and passage H3 and thereby cuts off the communication from the passage l2 to atmosphere through the exhaust port ||3, the release of uid under pressure from the straight-air pipe |2| and brake cylinder Il) to the passage ||2 past the unseated release valve |3| of the release magnet valve device ES under the control of the retardation controller device I8 is ineffective to cause reduction in the pressure in the straight-air pipe |2| and brake cylinder lil to a degree lower than the pressure setting of the safety valve device |45. The safety valve device |45 is effective to permit release of fluid under pressure from the passage |2 only so long as the pressure of the fluid released from the straightair pipe |2| to the passage ||2 exceeds a certain pressure, this pressure being somewhat higher than the pressure required to seat the ball valve |49 of the inshot valve device |48.

The minimum pressure to which the pressure in the straight-air pipe 2| and brake cylinder I0 may be reduced in emergency applications of the brakes by operation of the retardation controller I8 is accordingly determined by the pressure setting of the safety valve device M5. It should be understood that this minimum pressure is sufliciently high to insure the maintenance of an adequate braking force which will, however, not cause sliding of the wheels at the lower speeds of the car or train, under ordinary wheel and rail conditions.

In the event, however, that individual axles or wheels should begin to slip, that is reduce in speed toward a locked condition, the anti-wheelsliding device |9, for each brake cylinder', operates in the manner previously described for a service application of the brakes to relieve brake cylinder pressure, and accordingly the braking force, to prevent sliding of the wheels.

It will be observed that, if for any reason, such as sticking of the piston of the emergency valve device 4|] in release position, the reduction in safety control pipe pressure by operation of the brake pedal |2 is ineffective to actuate the emergency valve device 4@ to application position in the manner previously described, the self-lapping valve device 35 functions to supply fluid under pressure to the straight-air pipe i2l and thus to the brake cylinders in the same manner as for a service application of the brakes, except that brake cylinder will bey higher, possibly even a maximum degree. As previously stated, with the brake pedal l2 in emergency position, the supply valve 37 of the self-lapping valve device 35 is held open and thus the maximum pressure of the fluid built up in the straight-air pipe may correspond to the maximum suppliable from the main reservoir 9, depending upon the control exercised by the retardation controller i8.

(e) Release of the brakes following manual emergency applications- When it is desired to release the brakes following manual emergency applications of the brakes, the operator merely relieves the pressure on the brake pedal i2, as by removing his foot therefrom. Since the lock pipe 234 has been reduced in pressure and the locking pawl 225 accordingly rocked into interlocking engagement with the segment 22d, the brake pedal |2 cannot be returned toward its raised position by action of the spring 8f3 of the self-lapping valve device 35. However, upon the release of the foot-applied pressure on the brake pedal |2, the spring 38B acting' on the valve 318 of the vent valve device 28 is eiTective to seat thevalve 318 and thus close off the communication through which fluid under pressure is vented from the safety control pipe 98. Obviously, the spring 38B may shift the brake pedal l2 and accordingly the bell-crank lever 88, independently of the self-lapping valve 35 being locked in position, for the reason that the cable 8l is flexible. If a rigid tie rod is provided instead of a flexible cable 8l, the eyelet or clevis 86 must have a lost motion connection to the operating arm 83 of the self-lapping valve device 35.

With the valve 378 of the vent valve device 22 seated, the safety control pipe d8 is again charged with iluid under pressure from the main reservoir pipe i9 by way of the controller valve device I3, the foot-valve device lll and the non-return valve 228 in the manner previously described. As the safety control pipe pressure is restored, the pressure in the lock pipe 234., chamber 451' of the pneumatic switch device 26, the piston cham- .30 the pressure attained in the straight-air pipe and ber 96 of the emergency valve device, and the chamber 28| of the pressure cylinder 269, associated with the retardation controller device I8 is also restored. Accordingly, the emergency valve device 40 is again conditioned inthe normal position shown in Fig. 2, as is also the piston 2 68 associated with the retardation controller device I9. Upon the restoration of pressure in the lock pipe 234, the pawl 225 is shifted out of interlocking engagement With the toothed segment 225 and the spring 84 then becomes effective to return the self-lapping valve device 35, the controlled 25, and the brake pedal I2 to release position.` Fluid under pressure is accordingly released from the brake cylinder I0, under the control of the selflapping valve device 35, and raising of the track shoe device 23 out of contact with the4 rail 387 and deenergization of the electromagnet 386 of the track brake device 23 effected in the manner previously described, under the control of controller 25.

It will be observed that the actuation of 'pneumatic switch device 26 to circuit-opening position by the increase in safety control pipe pressure is ineffective, alone, to release the magnetic track shoe brakes because the controller device 25 is in parallel therewith and until the controller device 25 is returned to release Y,position as described above, the magnetic track shoe brakes will not be released. The operation of the magnetic track shoe brakes as described assumes ability of the electromagnet 389 on the track shoes to withstand continued excitation.

If the electromagnets 389 are not capable of withstanding a continuous excitation, then suitable devices must be provided to interrupt the circuits for the electromagnet 389 and magnet |89 of magnet valve device 26| independently of pneumatic switch device 26 and controller 25, so that the magnetic track brakes are released before the electromagnets 389 are destroyed by overheating.

(j). Deadmcms emergency application of the brakes.-Assuming the vehicle or train of cars to be traveling along the road with the equipment conditioned as shown in Figs. 1 and 2, wherein the brake pedal I2 is in its normal raised position, the pedal |95 of the foot-valvendevice i4 is released, and the handle IlI of the controller valve device I3 is depressed, a deadmans emergency application of the brakes may be eifected by releasing the handle I'lI of the controller valve device I3. Upon the release of the handle I'II ofthe controller valve device I 3, the Valve |18 is shifted to its upper seated position to cut off the supply of iiuid under pressure from the main reservoir pipe 59 and is unseated from its lower valve seat to establish connection from the safety control pipe 98 to atmosphere by way of the pipe 98a., branch pipe 291, chamber 263 of cut-01T valve device I5, port 295, chamber 292, branch pipe 286, pipe 98a, chamber ISI of the foot-valve device I4, past the unseated diaphragm valve |94, chamber |92, pipe 93, chamber II9 of the controller valve device I3, past the open lower valve seat of the valve |18 and exhaust port and passage |82. Accordingly,` in the same manner as for a manual emergency application of' the brakes, reduction of uid pressure in the safety control pipe 98 results in a reduction of fluid pressure in the piston chamber 95 of the emergency valve device, chamber 5l of pneumatic switch device 26, piston chamber 28| of the pressure cylinder 269 associated With the retardation controller device I8, and the lock pipe'234. As a result, the retardation controller device I8 is automatically set to regulate tothe maximum rate of retardation, the emergency Valve device is operated in the manner previously described to supply fluid under pressure from the main reservoir 9 to the straight-air pipe I2I and the brake cylinder I6, andthe pneumatic switch device causes application of the magnetic track shoe brakes. At the same time also, the'reduc'- tion in pressure in the lock pipe 234 causes the pawl 225 of locking device I6 to be shifted vinto interlocking engagement with the toothed surface of the segment 22Ii-- In view of the fact that the controller device 25 'is operated only when the brake pedal I2 is depressed, it will be apparent that, for a deadmans emergency application of the brakes, operation of the controller 25 out of its release position is not effected, but that application of the magnetic track Yshoe brake device 23 is nevertheless effected dueto operation of the pneumatic switch device 26.

Accordingly for a deadmans emergency application of the brakes, application of the fluid pressure brakes associated with the vehicle wheels and ofY the magnetic track shoe brakes is automatically eifected, the retardation controller device I 8 functioning to regulate 'the pressure in the straight-air pipe |2I and accordingly in the brake cylinder IG to prevent under ordinary conditions the application of the brakes with suchY excessive force while the car or train is reducing in speed under the application, as to cause sliding of the wheels.

It will be observed that the pressure of the iiuid in the straight-air pipe becomes effective in the communication through the cut-off valve de-z vice I5 through which fluid under pressure is exhausted from the safety control pipe 98 to atmosphere. Such operation of the cut-oi valve device I5 is not effected, however, until after the safety control pipe pressure has been reducedk suiiciently to effect the emergency applicationI I of the brakes.

t will be apparent that the non-return valve 268 prevents the back-flow of fluid under pres- Y sure from the safety control pipe 98, in lay-pass,50

relation to the cut-off valve device I5, and consequently that when the cut-off valve device I5 is closed, further reduction in the safety 'control pipe pressure is prevented.

(g). Suppression of deadmcms emergency applications-1i the operator desires to release the handle ill of the controller valve device I3 and the pedal |95 of the foot-valve Vdevice I4 at the same time, Without causing a deadmans emergency application of the brakes, he may do so by' iirst depressing the brake pedal I2 a suicient degree into the service application zone to produce a suiiicient degree of pressure inV the straight-air pipeY and accordingly in the 'brake cylinder iil'to actuate the cut-off valve device I5 to closed position. Thus, although aportion of the pipe 98a on one side of the cut-orf valve device i5 and of the non-return `valve 268 is thereafter vented to atmosphere through the exhaust port |182 oi the controller valve device I3, the portion of the pipe 98a on the other side of the cut-off valve device I5 and of the non-return device 268 to which the safety control pipe V98Y is Vconnected is not so vented because the cut-offv valve device I 5 is closed andthe non-return'valve 208 prevents back-flow of uid under pressure therepast.

It will be observed that the lock pipe 234 is, however, connected to that portion of the pipe 98a. which is vented by simultaneous release of the handle ITI of the controller valve device I3 and the pedal |95 of the foot-valve device I4 and, accordingly, the pressure in the lock pipe 234 is reduced and the pawl 225 of the locking device I6 shifted into interlocking engagement with the toothed surface of the segment 224.

The self-lapping valve device 35 is thus locked against return to release position by the locking device I6 and consequently the pressure supplied to the straight-air pipe and the brake cylinder IU is maintained effective in the cut-off valve device I5 to maintain the diaphragm valve 209 thereof seated.

It will thus be seen that if the operator first effects at least a certain degree of kservice application of the brakes by depressing the brake pedal I2, he may then release both the handle of the controller valve device I3 and the pedal of footvalve device I4 without effecting a deadmans emergency application of the brakes. Furthermore, since the locking device prevents return of the self-lapping valve Idevice to release position, it also prevents return of the brake pedal I2 to release position, and thus the operator may in addition relieve the pressure on the brake pedal I 2 and even remove his foot entirely from the brake pedal without effecting release of the brakes.

It will be apparent that with the self-lapping valve device 35 locked in a service application position in the manner just described, an emergency application of the brakes may be effected immediately, Without the necessity of returning the self-lapping valve device 35 to release position, by merely further depressing the brake pedal i I2 to emergency position to unseat the valve 318 of the vent valve device 22. As previously stated, the pawl 225 of the locking device I6 is effective, when in interlocking engagement with toothed surface of the segment 224, to prevent return of the self-lapping valve device 35 to release posi- -tion but is ineffective to prevent further depres- Summarizing, it will be seen that I have provided a safety car equipment comprising iiuid pressure brake apparatus, magnetic track shoe brake apparatus, a self-lapping valve device which is manually operable, as by a brake pedal, to effect service applications of the fluid pressure brake apparatus by straight-air operation,

v and a controller device operated simultaneously late pressure in the straight-air pipe and thus in the brake cylinders on all cars, according to the setting of the retardation controller. A manually operable device is provided for setting and adjusting the retardation controller to regulate the rate of retardation to any desired rate over a certain range, between a maximum and a minimum limit.

An anti-Wheel-sliding device of the fly-Wheel type is provided for rapidly releasing the pressure for each individual brake cylinder upon the tendency to slip of the Wheel and axle unit with which the brake shoes operated by the brake cylinder are associated. The anti-wheel sliding device functions rapidly enough during the interval of the time in which the Wheels and axle are reducing in speed from the speed corresponding to the speed of travel of the vehicle, to zero speed corresponding to locked position, that the pressure in the brake cylinder is relieved and the wheel and axle unit thereby permitted to reaccelerate toward the normal speed corresponding to the speed of travel of the vehicle before the Wheels attain a locked condition. A pneumatically operated control valve device, controlled by the anti-wheel-sliding device through a magnet valve device, functions to cut off the individual brake cylinder from the straight-air pipe and to release fluid under pressure from the individual brake cylinder to atmosphere, when a wheel and axle unit, with which the anti-Wheel-sliding device is associated, begins to slip.

An emergency valve device, operated upon a reduction in the pressure in a so-called safety control pipe, is effective to cause the supply of fluid under pressure to the straight-air pipe to effect an emergency application of the brakes, through two parallel communications one of which is under the control of the supply magnet valve controlled by the retardation controller and the other of which is under the control of an inshot valve device.

The inshot valve device is effective to cut off the supply of yfluid under pressure through the communication controlled thereby only when a predetermined pressure is built up in the straightair pipe, for the purpose of insuring at least suiiicient pressure in the straight-air pipe and in the brake cylinders upon an emergency application of the brakes to bring the car or train to a safe stop, notwithstanding a possible accidental failure of the supply magnet valve to open the communication controlled thereby.

The retardation controller is automatically adjusted to regulate the pressure in the straight-air pipe and in the brake cylinders to produce the maximum rate of retardation, upon the reduction in pressure in the safety control pipe.

A safety valve device is rendered effective by operation of the emergency valve device to application position for limiting the reduction in straight-air pipe and brake cylinder pressure caused by the retardation controller, to a certain minimum pressure.

A pneumatic switch device is actuated upon a reduction in safety control pipe pressure to effect application of the magnetic track shoe brakes to a maximum degree, independently of the controller device.

A hand operated controller valve device and a foot valve device, familiarly known as deadman control devices are provided for effecting a reduction in pressure in the safety control pipe when the operating handle of the controller and f ro .A cut-off'valvedevice is" operated, responsively to a build up of 'least a certainpredetermined .pressure the straight-air pipe. and accordingly inV the brake cylinders, to close the communication vthrough which the hand operated controller and foot-valve device may effect reduction in the safety controll pipe pressure. Thus, by first effecting a certain degree of application of the lbrakes so as to cause thejcut-off valve to operate to closed position, the hand controller and the foot-valve may se simultaneously released without a deadrnanf emergency application of the Abrakes liieing effected. v

A pavvl and ratchet device is automatically loperated, by venting of a portion of the safety control pipe Which is always Yvented by operation :of the deadman devices, to lock the self-lap- .;.ping Valve device against return toward. release position. Accordinglyfif the cut-olf. valve de- 'vic'e is rst closed by depressing the brake pedal, vthe brake pedai, as Well as the deadman devices, \may 'be released entirely Without eifecting an the cut-off valve device is operated to closed position to suppress a` rdeadman emergency application of the brakes, an emergency applicaltion of the brakes may be effected merely by further `depressing the. brake pedal to emergency position.

AIt will be understood that various omissions,

additions or `ijnodiications may be made in the embodiment ef vmy invention j as shown in the dra-Wings Without departing from the spirit of -my invention andit is, therefore, not my intention to limit the scope of my invention except as it is necessitated by the scope of the prior art. Having now described my invention, What I claim as new and desire to secure by Letters Patent, is: ,Y Y

1. In a safety car brake equipment, fluid pres- 7 suregbrake apparatus, electric rbrake aparatus, a

self-lapping valve device operative to control application Yand release of the fluid pressure brakes, a controller device operative to control application and release of the electric brakes, a manually operative ,element jfor effecting simultaneous operation of; the valere device and of the controller device, a pipe normally charged With nuid under pressure, an emergency valve device operative to an application position inresponse to a reduction of pressure in said pipe to effect an emergency applicationiof the uid pressure brakes, means operative in response to a reduction of pressure in said pipe Vto effect application of the electric brakes independently of said. controller devine, and a valve operative to effect reduction ofjpressure in said pipe, said valve being operated rby said manually operative element oniy upona certain predetermined de- I' -gree of movement ofthe element out of its'normal position.

2. In a Vehicle'brake equipment, a self-lapping .valve device having' a vrotary .operating shaft, yielding meansurging said shaft into a normal ythepedal of the foot-Valve*aresimultaneously re'- VVleased. l'

to cause fluid'under pressure to be supplied to produce application of the brakes tof' a degree in accordance With the degree of rotary movementfof said shaft out of its normal position, a pipe'normally charged With fluid under pressure, a toothed segment secured to said shaft, a pavvl, and means responsive'to a reduction of pressnre in said pipeffor effecting vactuation of the piavvl intoninterlooking engagement with the toothed segment to prevent returnY movement of said shaftby said Vyielding means Ytovvard its normal brake release position from an application position and thereby to maintain an application of the brakes.' Y

3. "in a vehicle brakeY equipment, a self-lapping valve Ydevice having a rotary operating shaft, yielding means urging said shaft into-a normalr release' position, manually operative means for rotarily moving said shaft out of :its normal position to effect operation the Valve device, said valve device being effective upon operation, to'cause fluid under pressure to be suppiied to produce application of the brakes to a degree in accordarce with the degree of rotary movement of said shaft out of its normal position, a pipe"Y normally charged With uid under pressure, a toothed segment secured to said shaft, a p-iwl, andmeans responsive to a reduction of pressure in said pipe for effecting Yactuation of the pavvl intro interlocking engagement with the toothed segment to prevent return movement -of said shaft by said yielding means toward its normal Ybrake release position from an application position and thereby to maintain an application of the brakes, said segment andfsaid pawl cooperatingY in such manner as to be vineffective to prevent further rotaryl movement of thesaid shaft avvay'nfrom its normal position toxoperate theY valve'device to'increase the degree of lbrake application. Y Y

4. In a vehicle brake equipment, an electric brake device, a fluid Vpressure vbrake device, a manually operativeY brake control element, means operated by the said element for controllingthe supply of Yiiuid under pressure to and the release of fluid under pressure from the said fluidl pnessure brake device whereby to control application and release of the iiuid pressure brakes, means operated 'simultaneously vith said last means by the said element for controlling the application and release ofthe electric brake de-` vice, a pipe normally charged with huid' under pressure,:and means operated in response to a reductionlfof pressure in said pipe for preventing operion ofthe said fluid pressure brake control means and of the electric brake control means by!Y said element to effectrrelease of the fluid pressure brakes and of the ,electric brakes. :5. In a, train brake equipment,` comprising a plurality of separate wheel brake units, means manually operat've to effect application and release of all the brake units, an' inertiadevice responsiveto rate lof change of speed of the train for-so controlling all thebrake units as to regu- Yate the rate of retardation of the train toa se- -wtedfrate and means/foreach brake unit re. sponsive only to a change in rotative speed ofthe Wheels, with which the brake units are associated,

at a rate exceeding a certain predetermined rate occasioned by the inception of wheel slipping r*for effectinga rapid reduction in the braking force'.

with which the brakes of the correspondingr braking unit are applied to prevent sliding of the wheels associated with that unit.

6. In a train brake equipment, in combination, a brake cylinder effective upon the supply of fluid under pressure thereto to cause application of the brakes on an associated car wheel and upon the release of iiuid under pressure therefrom to eiTect release of the brakes, a pipe, valve means normally establishing communication betweenv said brake cylinder and said pipe, means for causing iluid under pressure to be supplied to said pipe and brake cylinder to effect application of the brakes and for releasing fluid under pressure from said pipe and brake cylinder to eiect release of the brakes, an inertia device responsive to rate of change of speed of the train for so controlling the pressure in said pipe and accordingly in said brake cylinder as to regulate the rate of retardation of the train to a selected rate, and means responsive only to a change in rotative speed of the car Wheel, on which the brake cylinder causes application of the brakes, at a rate exceeding a certain predetermined rate occasioned by the inception of slipping of the Wheel, for effecting operation of said valve means to cut off said brake cylinder from said pipe and rapidly release fluid under pressure from the said brake cylinder to reduce the degree of the brake application and thus prevent sliding of the vehicle Wheels.

'7. In a safety car brake equipment, in combination, a control pipe normally charged with fluid under pressure, means operable upon a reduction in fluid pressure in said pipe for effecting an application of the brakes, valve means for venting uid under pressure from said pipe, a valve mechanism operable manually for effecting an application of the brakes, manually operable means adapted upon movement from release position over a certain range for effecting operation of said valve mechanism and upon a further movement for operating said valve means, means operable upon a reduction in pressure in said pipe for locking said valve mechanism against movement toward release position, said manually operable means having a movement relative to said Valve mechanism from the position in which said Valve means is open to permit closure of said valve means.

8. In a safety car brake equipment, in combination, a control pipe normally charged With fluid under pressure, means operable upon a reduction in fluid pressure in said pipe for effecting an application of the brakes, valve means for venting fluid under pressure from said pipe, a valve mechanism operable manually for effecting an application of the brakes, manually operable means adapted upon movement from release position over a certain range for effecting operation of said valve mechanism and upon a further movement for operating said valve means, means operable upon a reduction in pressure in said pipe for locking said valve mechanism against movement toward release position, said manually operable means being returnable at any time toward its normal release position, from the position in which said valve means is open, to permit closure of said valve means, notwithstanding that said locking means prevents return of said Valve mechanism toward release position.

ELLIS E. HEWI'IT. 

